When the mass no longer makes the weight

In everyday life, we constantly fight against the law of gravity, which is severe, and we spontaneously make this force the arbiter of the orientation of the space around us. It is the direction of our weight that “polarizes” the space in which we move. One could almost say that gravity “stylizes” our space, coordinates it, making the vertical dimension more essential than the horizontal.

Gravity also orients our body, polarizes it

This is especially true for mountaineers, who do not feel their weight in the same way depending on whether their feet are supported by some support offered by the wall or whether they are suspended in the void by their hands: “A suspended man certainly looks at the same as a man standing, pointed Louis Wittgenstein, but the game of forces in him is quite different, which allows him to act very differently from the one standing. (1)”

This small volume of space that does not lack air

The supreme fear of mountaineers is, of course, the fall. The fall “into the void”, as they say, although the void that is below them -and which they sometimes call, the gas – is much fuller than the one above them. In short, we call “empty” not what is empty, but the small volume of space (which does not lack air) that the mountaineers look out and into which they can fall. We see from this that even our vocabulary is twisted by gravity.

Gravitation, curvature… This of course leads us to Einstein. One day in 1907, the future father of the theory of general relativity had the idea of ​​what he would later say was “the happiest” of his life: he suddenly understood that if a person is in free fall, he will not feel his own weight . . “She won’t feel her own weight”, what does that mean? That if we fell in free fall, that is to say in a real vacuum -in an environment that offers no resistance to our fall-, all the objects close to us, for example our ice ax, would fall exactly -dixit Galilean – at the same speed as us. We would see them not fall, but levitate at the same level as us, floating (…)

bibliographic source

(1) Louis Wittgenstein, mixed comments (1937), trans. G. Bulk, Mauvezin, TER, 1984, p. 44-45. [éd. Poche Flammarion 2002]

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